Fluids are transferred in various types of systems and to provide various types of functions. Reaction control systems are used by launch vehicles and in other spacecraft/spacecraft applications as well. Various types of fluids are transferred within these types of systems to provide various types of functions. Components of one known prior art reaction control system include a ullage bottle which is disposed within a rigid rocket fuel storage bottle. The ullage bottle is fluidly interconnectable with a pneumatics system by a first fluid conduit which includes a first pyrotechnic isolation valve. A first service valve interfaces with this first fluid conduit at a location which is between the first pyrotechnic isolation valve and the ullage bottle to allow an appropriate fluid (e.g., helium) to be directed into and removed from the ullage bottle prior to activating the first pyrotechnic isolation valve and for purposes which are addressed below.
A second fluid conduit interconnects the rocket fuel storage bottle with a rocket fuel tank. One or more rocket engine modules in turn are fluidly interconnected with this rocket fuel tank. Therefore, the storage bottle is a "holding tank" of sorts for the rocket fuel. A second pyrotechnic isolation valve is disposed within the second fluid conduit to isolate the storage bottle from the rocket fuel tank until the desired time. A second service valve interfaces with the second fluid conduit at a location which is between the second pyrotechnic isolation valve and the rocket fuel storage bottle to allow an appropriate rocket fuel (e.g., hydrazine) to be loaded within and unloaded from the storage bottle prior to activation of the second pyrotechnic isolation valve and using the above-noted first service valve. More specifically, fluid may be directed into the ullage bottle through the first service valve to unload rocket fuel from the storage bottle and without providing the same to the rocket fuel tank. Fluid which is directed into the ullage bottle expands the same, which in turn forces rocket fuel out of the rocket fuel storage bottle and through the second service valve. A vacuum may be drawn through the first service valve as well to facilitate the loading of fuel within the rocket fuel storage bottle by directing the rocket fuel through the second service valve and into the storage bottle prior to an activation of the second pyrotechnic isolation valve, and thereby without directing any of such rocket fuel into the rocket fuel tank.
A third service valve of the noted prior art reaction control system interfaces with the second fluid conduit at a location which is between the second pyrotechnic isolation valve and the rocket fuel tank to allow a gas to be introduced into and removed from the rocket fuel tank and/or rocket engine modules interconnected therewith prior to activation of the second pyrotechnic isolation valve. For instance, it may be desirable to introduce an appropriate gas (e.g., nitrogen) into the rocket fuel tank and within the rocket engine modules to retain the same in a "clean" condition until a certain amount of time before the rocket engine modules are to be activated. At the appropriate time, this gas may be removed from the rocket fuel tank and rocket engine modules through the third service valve by drawing a vacuum through the same. Thereafter and at the appropriate time, the first and second fluid isolation valves may be simultaneously activated to remove the isolation between the ullage bottle and the pneumatics system and between the rocket fuel storage bottle and the rocket fuel tank. Fluid which is directed into the ullage bottle by the pneumatics system expands the same. Reduction of the inner volume of the storage bottle forces rocket fuel out of the same and through the second pyrotechnic isolation valve to the rocket fuel tank for use by the rocket engine modules.
The above-noted prior art system has the noted isolation and service valves each being separately interconnected with the reaction control system by welds or the like. Moreover, each of these service valves and pyrotechnic isolation valves are mounted on separate panels in this prior art system. The disadvantages of this particular system configuration and assembly technique include that it is much more costly and labor intensive to install.
The service valves utilized by the above-noted prior art reaction control system open and close the flow of fluids, such as liquids and gases, from one tank to another tank. Valves generally of this type are currently available from Moog and OEA, Inc., and utilize a metal-to-metal seal (e.g., metal ball against a metal channel) to close or seal the valve. In such cases, to avoid leakage, the metal ball and metal channel must be made with a high degree of precision to ensure an adequate seal is achieved. In addition, such metal-to-metal seals in such existing service valves require a specific torque to seal the valve (e.g., 45 inch pounds, plus or minus 2 inch pounds). Otherwise, the seal formed by the metal ball and metal channel may leak, which is particularly dangerous in instances where the fluid is a hypergolic fluid, such as hydrozene. For example, in instances where the metal-to-metal seal is under-torqued, leakage may occur. In other instances, where the metal-to-metal is over-torqued, the metal ball may be galled, which may also cause leakage. And since such valves are typically hand-tightened, the amount of torquing of the valves is generally inconsistent, and is often under-torqued or over-torqued. When such metal-to-metal seals leak, in order to replace such valves, the valves must be typically be cut-out since such valves are again typically welded in place. In addition, the normal flow area in such currently available valves is small, and, as such, filling a tank with a fluid through such currently existing valves requires a great deal of time. In instances where the fluid is a hypergolic fluid, due to the poisonous and explosive nature of the fluid, the area must be evacuated for an extended period of time during the flow of fluid through the valve. Finally, such existing valves require a series of brackets to support the valve since such valves are subject to side loading. Such side loading can adversely affect the seal by gallings side surfaces of the valve, which may also cause leakage.